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On the decidability and complexity of query answering over inconsistent and incomplete databases

Andrea Calì, Domenico Lembo, Riccardo Rosati
2003 Proceedings of the twenty-second ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems - PODS '03  
In particular, after showing that the problem is in general undecidable, we identify the maximal class of inclusion dependencies under which query answering is decidable in the presence of key dependencies  ...  In this paper, we address the problem of obtaining consistent answers in such a setting, when key and inclusion dependencies are expressed on the database schema.  ...  In this paper, we address the problem of query answering in a relational setting under the above semantics, when key and inclusion dependencies are expressed on the database schema.  ... 
doi:10.1145/773153.773179 dblp:conf/pods/CaliLR03 fatcat:yict35shavgkbmxv2lj7lvlvi4

On the decidability and finite controllability of query processing in databases with incomplete information

Riccardo Rosati
2006 Proceedings of the twenty-fifth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems - PODS '06  
The kinds of ICs that we consider are functional dependencies (in particular key dependencies) and inclusion dependencies; the query languages we consider are conjunctive queries (CQs), union of conjunctive  ...  In particular, we close two long-standing open problems in query containment, since we prove finite controllability of containment of conjunctive queries both under arbitrary inclusion dependencies and  ...  and inclusion dependencies.  ... 
doi:10.1145/1142351.1142404 dblp:conf/pods/Rosati06 fatcat:dzytazeif5gmbgug6k5ybdbxmq

Consistent query answering in databases

Leopoldo Bertossi
2006 SIGMOD record  
FDs: P (u, x, y) ∧ P (v, x, z) → y = z Full inclusion dependencies: P (x) → Q(x) Range constraints: P (x, y) → y < 100 ICs XSB Consistent Answers XSB Environment Some Limitations First order query  ...  Inclusion dependencies repaired through insertions Cycles in the set of inclusion dependencies Infinite underlying domain that can be used for insertions Remarks: Complexity of query evaluation  ...  to compute all the certain answers to monotone queries The program can be refined to compute all and only the minimal legal instances There are clear connections between query answering in VDISs and query  ... 
doi:10.1145/1147376.1147391 fatcat:jadcwoxqmrgcxp3rsjg4otz4ea

The Impact of Disjunction on Reasoning under Existential Rules: Research Summary [article]

Michael Morak
2014 arXiv   pre-print
For guarded theories with disjunction, we obtain a strong 2EXP lower bound in the combined complexity, even for very restricted formalisms like fixed sets of (disjunctive) inclusion dependencies.  ...  For sticky theories, the query answering problem becomes undecidable, even in the data complexity, and for weakly-acyclic query answering we see a reasonable and expected increase in complexity.  ...  most two. • coNP-completeness in the data complexity for query answering under DIDs up to guarded DTGDs. • EXP-completeness in the data complexity for query answering under weakly-guarded sets of DTGDs  ... 
arXiv:1405.5109v1 fatcat:4al4oxnkenb7pe3q64zqgtfet4

Access patterns and integrity constraints revisited

Vince Bárány, Michael Benedikt, Pierre Bourhis
2013 Proceedings of the 16th International Conference on Database Theory - ICDT '13  
We show that answerability is decidable for the class of guarded dependencies, which includes all inclusion dependencies, and also for constraints given in the guarded fragment of first-order logic.  ...  Unlike prior work, we focus on integrity constraint languages that subsume inclusion dependencies.  ...  We then turn to query answering under schemas that include access patterns and constraints. We distinguish several notions of what it means to answer a query under a schema.  ... 
doi:10.1145/2448496.2448522 dblp:conf/icdt/BaranyBB13 fatcat:aexm4ssya5fkbl5jteqnfwixtq

On the data complexity of consistent query answering

Balder ten Cate, Gaëlle Fontaine, Phokion G. Kolaitis
2012 Proceedings of the 15th International Conference on Database Theory - ICDT '12  
In particular, the consistent answers of a query on an inconsistent database provide sound semantics and the guarantee that the values obtained are those returned by the query on every repair of the given  ...  To this effect, we introduce the notion of a universal repair, as well as relaxations of it, and then apply it to the investigation of the data complexity of consistent query answering.  ...  It was also known that the consistent query answering problem was undecidable in combined complexity for unions of conjunctive queries and for sets of inclusion dependencies and functional dependencies  ... 
doi:10.1145/2274576.2274580 dblp:conf/icdt/CateFK12 fatcat:y7qzlu6r75fhffcdzhmdkax3a4

Consistent query answering via ASP from different perspectives: Theory and practice

2012 Theory and Practice of Logic Programming  
The process of answering user queries under global constraint violations is calledconsistent query answering(CQA).  ...  This paper provides a contribution in this setting: it uniforms solutions coming from different perspectives under a common Answer-Set Programming (ASP)-based core, and provides query-driven optimizations  ...  The only exception is on Query Q 3 which comprises inclusion dependencies only.  ... 
doi:10.1017/s1471068411000640 fatcat:mg6hh3fbp5horo622nq5w6xzmm

Minimal-change integrity maintenance using tuple deletions

Jan Chomicki, Jerzy Marcinkowski
2005 Information and Computation  
and consistent query answers [in: ACM Symposium on Principles of Database Systems (PODS), 1999, 68] (is a tuple an answer to a given query in every repair of a given database?).  ...  We consider denial constraints, general functional and inclusion dependencies, as well as key and foreign key constraints.  ...  Inclusion dependencies In Theorem 4.1 below, we formulate a general relationship between the problems of repair checking and consistent query answers in the presence of inclusion dependencies.  ... 
doi:10.1016/j.ic.2004.04.007 fatcat:aq7oguqeafh6piupdkrybo4tcm

Project-Join-Repair: An Approach to Consistent Query Answering Under Functional Dependencies [chapter]

Jef Wijsen
2006 Lecture Notes in Computer Science  
A repair of I is a maximal (under set inclusion) consistent subset of I.  ...  Note that σ(I) ⊇ I.We require Σ |= σ.Therefore, if I satisfies Σ, then σ(I) = I.Consistent query answering becomes the complexity of:CQAJD(Σ, σ, q) := {I | I is a relation and q Σ (σ(I)) = {}} Determine  ...  Conclusion Database repairing and consistent query answering under fd's.  ... 
doi:10.1007/11766254_1 fatcat:fkwkaa2smvfyfmgorq6m2bvzbi

On the Complexity of Query Answering under Matching Dependencies for Entity Resolution [article]

Leopoldo Bertossi, Jaffer Gardezi
2013 arXiv   pre-print
The resolved answers to queries are those that are invariant under the resulting class of resolved instances.  ...  In previous work we identified some tractable cases (i.e. for certain classes of queries and MDs) of resolved query answering.  ...  The idea is to rewrite a query, say conjunctive, into a new query such that the new query on the inconsistent database returns as usual answers the consistent answers to the original query.  ... 
arXiv:1304.7854v2 fatcat:je672nxxv5dizd27ggcmdimzqe

Database Reformulation with Integrity Constraints (extended abstract) [article]

Rada Chirkova, Michael R. Genesereth
2005 arXiv   pre-print
and inclusion dependencies.  ...  storage limit, provides equivalent rewritings of the queries under the constraints (this requirement is weaker than equivalence in the absence of constraints), and reduces the total costs of evaluating  ...  Note that unchase, unlike chase, can be used in presence of cyclic inclusion dependencies. Exploring unchase for answering queries using views is another direction of our future work.  ... 
arXiv:cs/0506026v1 fatcat:7fc2dlazonb6jeyiudwp6eszpa

Minimal-Change Integrity Maintenance Using Tuple Deletions [article]

Jan Chomicki, Jerzy Marcinkowski
2002 arXiv   pre-print
and consistent query answers (is a tuple an answer to a given query in every repair of a given database?).  ...  We consider denial constraints, general functional and inclusion dependencies, as well as key and foreign key constraints.  ...  The problem of consistent query answers is already intractable, even under additional restrictions on the FDs and INDs.  ... 
arXiv:cs/0212004v1 fatcat:thluoz2dhvf3tdyfcrmdsnghri

Repair checking in inconsistent databases

Foto N. Afrati, Phokion G. Kolaitis
2009 Proceedings of the 12th International Conference on Database Theory - ICDT '09  
Hence, LAV tgds are preserved under unions of models. Key property of weakly acyclic sets of tgds: The solution aware chase terminates in polynomial time.  ...  Consistent Query Answering Proposition (Chomicki and Marcinkowski -2003) Let Σ be a set of integrity constraints containing all inclusion dependencies.  ...  Repair checking is a data cleaning problem that underlies consistent query answering. So far, repair checking has received less attention than consistent query answering. Repair Checking vs.  ... 
doi:10.1145/1514894.1514899 dblp:conf/icdt/AfratiK09 fatcat:lvijjkbivnallpzuugigf2w634

Experimenting Data Integration with DIS@DIS [chapter]

Andrea Calì, Domenico Lembo, Riccardo Rosati, Marco Ruzzi
2004 Lecture Notes in Computer Science  
Since data at the sources may not satisfy the constraints, DIS@DIS is capable of reasoning in the presence of incomplete and inconsistent information, so as to provide consistent answers to user queries  ...  DIS@DIS incorporates novel optimization techniques for query processing, which speed up query answering time even in the presence of complex global schemata and large amounts of data.  ...  Query Answering in GAV In order to deal with inclusion dependencies, DIS@DIS makes use of the algorithm IDrewrite [6] , which is able to rewrite the user query according to the IDs expressed over the  ... 
doi:10.1007/978-3-540-25975-6_6 fatcat:cttvqylnmvb35i4phpkoumkwiy

On the Computational Complexity of Minimal-Change Integrity Maintenance in Relational Databases [chapter]

Jan Chomicki, Jerzy Marcinkowski
2005 Lecture Notes in Computer Science  
and consistent query answers (is a tuple an answer to a given query in every repair of a given database?).  ...  In Section 4, we discuss more general universal constraints and inclusion dependencies, under different notions of repair.  ...  Let Q be a union of conjunctive queries. Then the problem of consistent query answers is in P (under sound semantics).  ... 
doi:10.1007/978-3-540-30597-2_5 fatcat:bjj7be3b4vaelksqnhsgwpizrm
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